from VMware's performance team

Monthly Archives: April 2017

Weathervane is a performance benchmarking tool developed at VMware. It lets you assess the performance of your virtualized or cloud environment by driving a load against a realistic application and capturing relevant performance metrics. You might use it to compare the performance characteristics of two different environments, or to understand the performance impact of some change in an existing environment.

Weathervane is very flexible, allowing you to configure almost every aspect of a test, and yet is easy to use thanks to tools that help prepare your test environment and a powerful run harness that automates almost every aspect of your performance tests. You can typically go from a fresh start to running performance tests with a large multi-tier application in a single day.

Resource management in vSphere is very robust and sophisticated. It provides settings like reservation, limits and shares (a.k.a. RLS), which can be applied on virtual machines (VMs) and resource pools. These settings can be used as knobs to isolate resources, prioritize them, or to guarantee availability of resources to VMs in a cluster. Our customers have often asked about how these settings impact availability of resources for a VM.

Recently we published a white paper based on our study, to explain how reservation and shares can impact resource availability for VMs when they are applied on VMs versus when they are applied on resource pools. In the paper, we also share some general guidelines on when and how these settings can be used.

At the VMworld 2016 Barcelona keynote, CTO Ray O’Farrell proudly presented the performance improvements in vCenter 6.5. He showed the following slide:

Slide from Ray O’Farrell’s keynote at VMworld 2016 Barcelona, showing 2x improvement in scale from 6.0 to 6.5 and 6x improvement in throughput from 5.5 to 6.5.

As a senior performance engineer who focuses on vCenter, and as one of the presenters of VMworld Session INF8108 (listed in the top-right corner of the slide above), I have received a number of questions regarding the “6x” and “2x scale” labels in the slide above. This blog is an attempt to explain these numbers by describing (at a high level) the performance improvements for vCenter in 6.5. I will focus specifically on the vCenter Appliance in this post.